when added still adds the writing part, even though I checked of the [W] when adding them to the list.
I only want to study the reading and definition on some words, and eventually the reading later.
Right now I have to press the magnifying glass and tick of the writing part.

You need to disable the "Study all kanji in list" setting:
http://www.skritter.com/account/settings-study

That's overriding the marking you have to not study certain writings in the list.

Note that changing the above setting won't work retroactively, so you'll still need to get rid of the kanji parts you've already added to My Words, that you don't want.

Hope this helps!

Thank you, nick!